paul. >> reporter: liz, allen, it is certainly chilly. it was the coldest afternoon in the bay area on average since 5 days before valentine's day in early february. mobile weather lab in castro valley it is 46.8. it's already dropped three degrees in the past 20 minutes. when the sun goes down, temperatures drop like a rock. let's establish how warm or not we got today. san jose a high of 52. concord 51. napa 53. livermore only 51. setting the stage for a widespread freeze tonight, most of the bay area is under that freeze warning. the only exception is the city of san francisco. widespread lows in the mid-20s to the low 30s so watch out. protect plants if you can and make sure the pets come inside. these are some of your overnight lows. santa rosa tonight 24. tomorrow morning in livermore 25. concord 27. redwood city 30. so a widespread freeze is coming up. we sent len ramirez to gilroy today to talk about how the farmers are going to deal with this very hard freeze. >>> reporter: paul, it's going to be a very long night for growers her